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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_SWAPOPS_H
3#define _LINUX_SWAPOPS_H
4
5#include <linux/radix-tree.h>
6#include <linux/bug.h>
7#include <linux/mm_types.h>
8
9#ifdef CONFIG_MMU
10
11/*
12 * swapcache pages are stored in the swapper_space radix tree. We want to
13 * get good packing density in that tree, so the index should be dense in
14 * the low-order bits.
15 *
16 * We arrange the `type' and `offset' fields so that `type' is at the seven
17 * high-order bits of the swp_entry_t and `offset' is right-aligned in the
18 * remaining bits. Although `type' itself needs only five bits, we allow for
19 * shmem/tmpfs to shift it all up a further two bits: see swp_to_radix_entry().
20 *
21 * swp_entry_t's are *never* stored anywhere in their arch-dependent format.
22 */
23#define SWP_TYPE_SHIFT (BITS_PER_XA_VALUE - MAX_SWAPFILES_SHIFT)
24#define SWP_OFFSET_MASK ((1UL << SWP_TYPE_SHIFT) - 1)
25
26/* Clear all flags but only keep swp_entry_t related information */
27static inline pte_t pte_swp_clear_flags(pte_t pte)
28{
29 if (pte_swp_soft_dirty(pte))
30 pte = pte_swp_clear_soft_dirty(pte);
31 if (pte_swp_uffd_wp(pte))
32 pte = pte_swp_clear_uffd_wp(pte);
33 return pte;
34}
35
36/*
37 * Store a type+offset into a swp_entry_t in an arch-independent format
38 */
39static inline swp_entry_t swp_entry(unsigned long type, pgoff_t offset)
40{
41 swp_entry_t ret;
42
43 ret.val = (type << SWP_TYPE_SHIFT) | (offset & SWP_OFFSET_MASK);
44 return ret;
45}
46
47/*
48 * Extract the `type' field from a swp_entry_t. The swp_entry_t is in
49 * arch-independent format
50 */
51static inline unsigned swp_type(swp_entry_t entry)
52{
53 return (entry.val >> SWP_TYPE_SHIFT);
54}
55
56/*
57 * Extract the `offset' field from a swp_entry_t. The swp_entry_t is in
58 * arch-independent format
59 */
60static inline pgoff_t swp_offset(swp_entry_t entry)
61{
62 return entry.val & SWP_OFFSET_MASK;
63}
64
65/* check whether a pte points to a swap entry */
66static inline int is_swap_pte(pte_t pte)
67{
68 return !pte_none(pte) && !pte_present(pte);
69}
70
71/*
72 * Convert the arch-dependent pte representation of a swp_entry_t into an
73 * arch-independent swp_entry_t.
74 */
75static inline swp_entry_t pte_to_swp_entry(pte_t pte)
76{
77 swp_entry_t arch_entry;
78
79 pte = pte_swp_clear_flags(pte);
80 arch_entry = __pte_to_swp_entry(pte);
81 return swp_entry(__swp_type(arch_entry), __swp_offset(arch_entry));
82}
83
84/*
85 * Convert the arch-independent representation of a swp_entry_t into the
86 * arch-dependent pte representation.
87 */
88static inline pte_t swp_entry_to_pte(swp_entry_t entry)
89{
90 swp_entry_t arch_entry;
91
92 arch_entry = __swp_entry(swp_type(entry), swp_offset(entry));
93 return __swp_entry_to_pte(arch_entry);
94}
95
96static inline swp_entry_t radix_to_swp_entry(void *arg)
97{
98 swp_entry_t entry;
99
100 entry.val = xa_to_value(arg);
101 return entry;
102}
103
104static inline void *swp_to_radix_entry(swp_entry_t entry)
105{
106 return xa_mk_value(entry.val);
107}
108
109#if IS_ENABLED(CONFIG_DEVICE_PRIVATE)
110static inline swp_entry_t make_readable_device_private_entry(pgoff_t offset)
111{
112 return swp_entry(SWP_DEVICE_READ, offset);
113}
114
115static inline swp_entry_t make_writable_device_private_entry(pgoff_t offset)
116{
117 return swp_entry(SWP_DEVICE_WRITE, offset);
118}
119
120static inline bool is_device_private_entry(swp_entry_t entry)
121{
122 int type = swp_type(entry);
123 return type == SWP_DEVICE_READ || type == SWP_DEVICE_WRITE;
124}
125
126static inline bool is_writable_device_private_entry(swp_entry_t entry)
127{
128 return unlikely(swp_type(entry) == SWP_DEVICE_WRITE);
129}
130
131static inline swp_entry_t make_readable_device_exclusive_entry(pgoff_t offset)
132{
133 return swp_entry(SWP_DEVICE_EXCLUSIVE_READ, offset);
134}
135
136static inline swp_entry_t make_writable_device_exclusive_entry(pgoff_t offset)
137{
138 return swp_entry(SWP_DEVICE_EXCLUSIVE_WRITE, offset);
139}
140
141static inline bool is_device_exclusive_entry(swp_entry_t entry)
142{
143 return swp_type(entry) == SWP_DEVICE_EXCLUSIVE_READ ||
144 swp_type(entry) == SWP_DEVICE_EXCLUSIVE_WRITE;
145}
146
147static inline bool is_writable_device_exclusive_entry(swp_entry_t entry)
148{
149 return unlikely(swp_type(entry) == SWP_DEVICE_EXCLUSIVE_WRITE);
150}
151#else /* CONFIG_DEVICE_PRIVATE */
152static inline swp_entry_t make_readable_device_private_entry(pgoff_t offset)
153{
154 return swp_entry(0, 0);
155}
156
157static inline swp_entry_t make_writable_device_private_entry(pgoff_t offset)
158{
159 return swp_entry(0, 0);
160}
161
162static inline bool is_device_private_entry(swp_entry_t entry)
163{
164 return false;
165}
166
167static inline bool is_writable_device_private_entry(swp_entry_t entry)
168{
169 return false;
170}
171
172static inline swp_entry_t make_readable_device_exclusive_entry(pgoff_t offset)
173{
174 return swp_entry(0, 0);
175}
176
177static inline swp_entry_t make_writable_device_exclusive_entry(pgoff_t offset)
178{
179 return swp_entry(0, 0);
180}
181
182static inline bool is_device_exclusive_entry(swp_entry_t entry)
183{
184 return false;
185}
186
187static inline bool is_writable_device_exclusive_entry(swp_entry_t entry)
188{
189 return false;
190}
191#endif /* CONFIG_DEVICE_PRIVATE */
192
193#ifdef CONFIG_MIGRATION
194static inline int is_migration_entry(swp_entry_t entry)
195{
196 return unlikely(swp_type(entry) == SWP_MIGRATION_READ ||
197 swp_type(entry) == SWP_MIGRATION_WRITE);
198}
199
200static inline int is_writable_migration_entry(swp_entry_t entry)
201{
202 return unlikely(swp_type(entry) == SWP_MIGRATION_WRITE);
203}
204
205static inline swp_entry_t make_readable_migration_entry(pgoff_t offset)
206{
207 return swp_entry(SWP_MIGRATION_READ, offset);
208}
209
210static inline swp_entry_t make_writable_migration_entry(pgoff_t offset)
211{
212 return swp_entry(SWP_MIGRATION_WRITE, offset);
213}
214
215extern void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep,
216 spinlock_t *ptl);
217extern void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
218 unsigned long address);
219extern void migration_entry_wait_huge(struct vm_area_struct *vma,
220 struct mm_struct *mm, pte_t *pte);
221#else
222static inline swp_entry_t make_readable_migration_entry(pgoff_t offset)
223{
224 return swp_entry(0, 0);
225}
226
227static inline swp_entry_t make_writable_migration_entry(pgoff_t offset)
228{
229 return swp_entry(0, 0);
230}
231
232static inline int is_migration_entry(swp_entry_t swp)
233{
234 return 0;
235}
236
237static inline void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep,
238 spinlock_t *ptl) { }
239static inline void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
240 unsigned long address) { }
241static inline void migration_entry_wait_huge(struct vm_area_struct *vma,
242 struct mm_struct *mm, pte_t *pte) { }
243static inline int is_writable_migration_entry(swp_entry_t entry)
244{
245 return 0;
246}
247
248#endif
249
250static inline struct page *pfn_swap_entry_to_page(swp_entry_t entry)
251{
252 struct page *p = pfn_to_page(swp_offset(entry));
253
254 /*
255 * Any use of migration entries may only occur while the
256 * corresponding page is locked
257 */
258 BUG_ON(is_migration_entry(entry) && !PageLocked(p));
259
260 return p;
261}
262
263/*
264 * A pfn swap entry is a special type of swap entry that always has a pfn stored
265 * in the swap offset. They are used to represent unaddressable device memory
266 * and to restrict access to a page undergoing migration.
267 */
268static inline bool is_pfn_swap_entry(swp_entry_t entry)
269{
270 return is_migration_entry(entry) || is_device_private_entry(entry) ||
271 is_device_exclusive_entry(entry);
272}
273
274struct page_vma_mapped_walk;
275
276#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
277extern void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw,
278 struct page *page);
279
280extern void remove_migration_pmd(struct page_vma_mapped_walk *pvmw,
281 struct page *new);
282
283extern void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd);
284
285static inline swp_entry_t pmd_to_swp_entry(pmd_t pmd)
286{
287 swp_entry_t arch_entry;
288
289 if (pmd_swp_soft_dirty(pmd))
290 pmd = pmd_swp_clear_soft_dirty(pmd);
291 if (pmd_swp_uffd_wp(pmd))
292 pmd = pmd_swp_clear_uffd_wp(pmd);
293 arch_entry = __pmd_to_swp_entry(pmd);
294 return swp_entry(__swp_type(arch_entry), __swp_offset(arch_entry));
295}
296
297static inline pmd_t swp_entry_to_pmd(swp_entry_t entry)
298{
299 swp_entry_t arch_entry;
300
301 arch_entry = __swp_entry(swp_type(entry), swp_offset(entry));
302 return __swp_entry_to_pmd(arch_entry);
303}
304
305static inline int is_pmd_migration_entry(pmd_t pmd)
306{
307 return !pmd_present(pmd) && is_migration_entry(pmd_to_swp_entry(pmd));
308}
309#else
310static inline void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw,
311 struct page *page)
312{
313 BUILD_BUG();
314}
315
316static inline void remove_migration_pmd(struct page_vma_mapped_walk *pvmw,
317 struct page *new)
318{
319 BUILD_BUG();
320}
321
322static inline void pmd_migration_entry_wait(struct mm_struct *m, pmd_t *p) { }
323
324static inline swp_entry_t pmd_to_swp_entry(pmd_t pmd)
325{
326 return swp_entry(0, 0);
327}
328
329static inline pmd_t swp_entry_to_pmd(swp_entry_t entry)
330{
331 return __pmd(0);
332}
333
334static inline int is_pmd_migration_entry(pmd_t pmd)
335{
336 return 0;
337}
338#endif
339
340#ifdef CONFIG_MEMORY_FAILURE
341
342extern atomic_long_t num_poisoned_pages __read_mostly;
343
344/*
345 * Support for hardware poisoned pages
346 */
347static inline swp_entry_t make_hwpoison_entry(struct page *page)
348{
349 BUG_ON(!PageLocked(page));
350 return swp_entry(SWP_HWPOISON, page_to_pfn(page));
351}
352
353static inline int is_hwpoison_entry(swp_entry_t entry)
354{
355 return swp_type(entry) == SWP_HWPOISON;
356}
357
358static inline unsigned long hwpoison_entry_to_pfn(swp_entry_t entry)
359{
360 return swp_offset(entry);
361}
362
363static inline void num_poisoned_pages_inc(void)
364{
365 atomic_long_inc(&num_poisoned_pages);
366}
367
368static inline void num_poisoned_pages_dec(void)
369{
370 atomic_long_dec(&num_poisoned_pages);
371}
372
373#else
374
375static inline swp_entry_t make_hwpoison_entry(struct page *page)
376{
377 return swp_entry(0, 0);
378}
379
380static inline int is_hwpoison_entry(swp_entry_t swp)
381{
382 return 0;
383}
384
385static inline void num_poisoned_pages_inc(void)
386{
387}
388#endif
389
390#if defined(CONFIG_MEMORY_FAILURE) || defined(CONFIG_MIGRATION) || \
391 defined(CONFIG_DEVICE_PRIVATE)
392static inline int non_swap_entry(swp_entry_t entry)
393{
394 return swp_type(entry) >= MAX_SWAPFILES;
395}
396#else
397static inline int non_swap_entry(swp_entry_t entry)
398{
399 return 0;
400}
401#endif
402
403#endif /* CONFIG_MMU */
404#endif /* _LINUX_SWAPOPS_H */
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_SWAPOPS_H
3#define _LINUX_SWAPOPS_H
4
5#include <linux/radix-tree.h>
6#include <linux/bug.h>
7#include <linux/mm_types.h>
8
9#ifdef CONFIG_MMU
10
11#ifdef CONFIG_SWAP
12#include <linux/swapfile.h>
13#endif /* CONFIG_SWAP */
14
15/*
16 * swapcache pages are stored in the swapper_space radix tree. We want to
17 * get good packing density in that tree, so the index should be dense in
18 * the low-order bits.
19 *
20 * We arrange the `type' and `offset' fields so that `type' is at the six
21 * high-order bits of the swp_entry_t and `offset' is right-aligned in the
22 * remaining bits. Although `type' itself needs only five bits, we allow for
23 * shmem/tmpfs to shift it all up a further one bit: see swp_to_radix_entry().
24 *
25 * swp_entry_t's are *never* stored anywhere in their arch-dependent format.
26 */
27#define SWP_TYPE_SHIFT (BITS_PER_XA_VALUE - MAX_SWAPFILES_SHIFT)
28#define SWP_OFFSET_MASK ((1UL << SWP_TYPE_SHIFT) - 1)
29
30/*
31 * Definitions only for PFN swap entries (see is_pfn_swap_entry()). To
32 * store PFN, we only need SWP_PFN_BITS bits. Each of the pfn swap entries
33 * can use the extra bits to store other information besides PFN.
34 */
35#ifdef MAX_PHYSMEM_BITS
36#define SWP_PFN_BITS (MAX_PHYSMEM_BITS - PAGE_SHIFT)
37#else /* MAX_PHYSMEM_BITS */
38#define SWP_PFN_BITS min_t(int, \
39 sizeof(phys_addr_t) * 8 - PAGE_SHIFT, \
40 SWP_TYPE_SHIFT)
41#endif /* MAX_PHYSMEM_BITS */
42#define SWP_PFN_MASK (BIT(SWP_PFN_BITS) - 1)
43
44/**
45 * Migration swap entry specific bitfield definitions. Layout:
46 *
47 * |----------+--------------------|
48 * | swp_type | swp_offset |
49 * |----------+--------+-+-+-------|
50 * | | resv |D|A| PFN |
51 * |----------+--------+-+-+-------|
52 *
53 * @SWP_MIG_YOUNG_BIT: Whether the page used to have young bit set (bit A)
54 * @SWP_MIG_DIRTY_BIT: Whether the page used to have dirty bit set (bit D)
55 *
56 * Note: A/D bits will be stored in migration entries iff there're enough
57 * free bits in arch specific swp offset. By default we'll ignore A/D bits
58 * when migrating a page. Please refer to migration_entry_supports_ad()
59 * for more information. If there're more bits besides PFN and A/D bits,
60 * they should be reserved and always be zeros.
61 */
62#define SWP_MIG_YOUNG_BIT (SWP_PFN_BITS)
63#define SWP_MIG_DIRTY_BIT (SWP_PFN_BITS + 1)
64#define SWP_MIG_TOTAL_BITS (SWP_PFN_BITS + 2)
65
66#define SWP_MIG_YOUNG BIT(SWP_MIG_YOUNG_BIT)
67#define SWP_MIG_DIRTY BIT(SWP_MIG_DIRTY_BIT)
68
69static inline bool is_pfn_swap_entry(swp_entry_t entry);
70
71/* Clear all flags but only keep swp_entry_t related information */
72static inline pte_t pte_swp_clear_flags(pte_t pte)
73{
74 if (pte_swp_exclusive(pte))
75 pte = pte_swp_clear_exclusive(pte);
76 if (pte_swp_soft_dirty(pte))
77 pte = pte_swp_clear_soft_dirty(pte);
78 if (pte_swp_uffd_wp(pte))
79 pte = pte_swp_clear_uffd_wp(pte);
80 return pte;
81}
82
83/*
84 * Store a type+offset into a swp_entry_t in an arch-independent format
85 */
86static inline swp_entry_t swp_entry(unsigned long type, pgoff_t offset)
87{
88 swp_entry_t ret;
89
90 ret.val = (type << SWP_TYPE_SHIFT) | (offset & SWP_OFFSET_MASK);
91 return ret;
92}
93
94/*
95 * Extract the `type' field from a swp_entry_t. The swp_entry_t is in
96 * arch-independent format
97 */
98static inline unsigned swp_type(swp_entry_t entry)
99{
100 return (entry.val >> SWP_TYPE_SHIFT);
101}
102
103/*
104 * Extract the `offset' field from a swp_entry_t. The swp_entry_t is in
105 * arch-independent format
106 */
107static inline pgoff_t swp_offset(swp_entry_t entry)
108{
109 return entry.val & SWP_OFFSET_MASK;
110}
111
112/*
113 * This should only be called upon a pfn swap entry to get the PFN stored
114 * in the swap entry. Please refers to is_pfn_swap_entry() for definition
115 * of pfn swap entry.
116 */
117static inline unsigned long swp_offset_pfn(swp_entry_t entry)
118{
119 VM_BUG_ON(!is_pfn_swap_entry(entry));
120 return swp_offset(entry) & SWP_PFN_MASK;
121}
122
123/* check whether a pte points to a swap entry */
124static inline int is_swap_pte(pte_t pte)
125{
126 return !pte_none(pte) && !pte_present(pte);
127}
128
129/*
130 * Convert the arch-dependent pte representation of a swp_entry_t into an
131 * arch-independent swp_entry_t.
132 */
133static inline swp_entry_t pte_to_swp_entry(pte_t pte)
134{
135 swp_entry_t arch_entry;
136
137 pte = pte_swp_clear_flags(pte);
138 arch_entry = __pte_to_swp_entry(pte);
139 return swp_entry(__swp_type(arch_entry), __swp_offset(arch_entry));
140}
141
142/*
143 * Convert the arch-independent representation of a swp_entry_t into the
144 * arch-dependent pte representation.
145 */
146static inline pte_t swp_entry_to_pte(swp_entry_t entry)
147{
148 swp_entry_t arch_entry;
149
150 arch_entry = __swp_entry(swp_type(entry), swp_offset(entry));
151 return __swp_entry_to_pte(arch_entry);
152}
153
154static inline swp_entry_t radix_to_swp_entry(void *arg)
155{
156 swp_entry_t entry;
157
158 entry.val = xa_to_value(arg);
159 return entry;
160}
161
162static inline void *swp_to_radix_entry(swp_entry_t entry)
163{
164 return xa_mk_value(entry.val);
165}
166
167#if IS_ENABLED(CONFIG_DEVICE_PRIVATE)
168static inline swp_entry_t make_readable_device_private_entry(pgoff_t offset)
169{
170 return swp_entry(SWP_DEVICE_READ, offset);
171}
172
173static inline swp_entry_t make_writable_device_private_entry(pgoff_t offset)
174{
175 return swp_entry(SWP_DEVICE_WRITE, offset);
176}
177
178static inline bool is_device_private_entry(swp_entry_t entry)
179{
180 int type = swp_type(entry);
181 return type == SWP_DEVICE_READ || type == SWP_DEVICE_WRITE;
182}
183
184static inline bool is_writable_device_private_entry(swp_entry_t entry)
185{
186 return unlikely(swp_type(entry) == SWP_DEVICE_WRITE);
187}
188
189static inline swp_entry_t make_readable_device_exclusive_entry(pgoff_t offset)
190{
191 return swp_entry(SWP_DEVICE_EXCLUSIVE_READ, offset);
192}
193
194static inline swp_entry_t make_writable_device_exclusive_entry(pgoff_t offset)
195{
196 return swp_entry(SWP_DEVICE_EXCLUSIVE_WRITE, offset);
197}
198
199static inline bool is_device_exclusive_entry(swp_entry_t entry)
200{
201 return swp_type(entry) == SWP_DEVICE_EXCLUSIVE_READ ||
202 swp_type(entry) == SWP_DEVICE_EXCLUSIVE_WRITE;
203}
204
205static inline bool is_writable_device_exclusive_entry(swp_entry_t entry)
206{
207 return unlikely(swp_type(entry) == SWP_DEVICE_EXCLUSIVE_WRITE);
208}
209#else /* CONFIG_DEVICE_PRIVATE */
210static inline swp_entry_t make_readable_device_private_entry(pgoff_t offset)
211{
212 return swp_entry(0, 0);
213}
214
215static inline swp_entry_t make_writable_device_private_entry(pgoff_t offset)
216{
217 return swp_entry(0, 0);
218}
219
220static inline bool is_device_private_entry(swp_entry_t entry)
221{
222 return false;
223}
224
225static inline bool is_writable_device_private_entry(swp_entry_t entry)
226{
227 return false;
228}
229
230static inline swp_entry_t make_readable_device_exclusive_entry(pgoff_t offset)
231{
232 return swp_entry(0, 0);
233}
234
235static inline swp_entry_t make_writable_device_exclusive_entry(pgoff_t offset)
236{
237 return swp_entry(0, 0);
238}
239
240static inline bool is_device_exclusive_entry(swp_entry_t entry)
241{
242 return false;
243}
244
245static inline bool is_writable_device_exclusive_entry(swp_entry_t entry)
246{
247 return false;
248}
249#endif /* CONFIG_DEVICE_PRIVATE */
250
251#ifdef CONFIG_MIGRATION
252static inline int is_migration_entry(swp_entry_t entry)
253{
254 return unlikely(swp_type(entry) == SWP_MIGRATION_READ ||
255 swp_type(entry) == SWP_MIGRATION_READ_EXCLUSIVE ||
256 swp_type(entry) == SWP_MIGRATION_WRITE);
257}
258
259static inline int is_writable_migration_entry(swp_entry_t entry)
260{
261 return unlikely(swp_type(entry) == SWP_MIGRATION_WRITE);
262}
263
264static inline int is_readable_migration_entry(swp_entry_t entry)
265{
266 return unlikely(swp_type(entry) == SWP_MIGRATION_READ);
267}
268
269static inline int is_readable_exclusive_migration_entry(swp_entry_t entry)
270{
271 return unlikely(swp_type(entry) == SWP_MIGRATION_READ_EXCLUSIVE);
272}
273
274static inline swp_entry_t make_readable_migration_entry(pgoff_t offset)
275{
276 return swp_entry(SWP_MIGRATION_READ, offset);
277}
278
279static inline swp_entry_t make_readable_exclusive_migration_entry(pgoff_t offset)
280{
281 return swp_entry(SWP_MIGRATION_READ_EXCLUSIVE, offset);
282}
283
284static inline swp_entry_t make_writable_migration_entry(pgoff_t offset)
285{
286 return swp_entry(SWP_MIGRATION_WRITE, offset);
287}
288
289/*
290 * Returns whether the host has large enough swap offset field to support
291 * carrying over pgtable A/D bits for page migrations. The result is
292 * pretty much arch specific.
293 */
294static inline bool migration_entry_supports_ad(void)
295{
296#ifdef CONFIG_SWAP
297 return swap_migration_ad_supported;
298#else /* CONFIG_SWAP */
299 return false;
300#endif /* CONFIG_SWAP */
301}
302
303static inline swp_entry_t make_migration_entry_young(swp_entry_t entry)
304{
305 if (migration_entry_supports_ad())
306 return swp_entry(swp_type(entry),
307 swp_offset(entry) | SWP_MIG_YOUNG);
308 return entry;
309}
310
311static inline bool is_migration_entry_young(swp_entry_t entry)
312{
313 if (migration_entry_supports_ad())
314 return swp_offset(entry) & SWP_MIG_YOUNG;
315 /* Keep the old behavior of aging page after migration */
316 return false;
317}
318
319static inline swp_entry_t make_migration_entry_dirty(swp_entry_t entry)
320{
321 if (migration_entry_supports_ad())
322 return swp_entry(swp_type(entry),
323 swp_offset(entry) | SWP_MIG_DIRTY);
324 return entry;
325}
326
327static inline bool is_migration_entry_dirty(swp_entry_t entry)
328{
329 if (migration_entry_supports_ad())
330 return swp_offset(entry) & SWP_MIG_DIRTY;
331 /* Keep the old behavior of clean page after migration */
332 return false;
333}
334
335extern void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep,
336 spinlock_t *ptl);
337extern void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
338 unsigned long address);
339#ifdef CONFIG_HUGETLB_PAGE
340extern void __migration_entry_wait_huge(pte_t *ptep, spinlock_t *ptl);
341extern void migration_entry_wait_huge(struct vm_area_struct *vma, pte_t *pte);
342#endif /* CONFIG_HUGETLB_PAGE */
343#else /* CONFIG_MIGRATION */
344static inline swp_entry_t make_readable_migration_entry(pgoff_t offset)
345{
346 return swp_entry(0, 0);
347}
348
349static inline swp_entry_t make_readable_exclusive_migration_entry(pgoff_t offset)
350{
351 return swp_entry(0, 0);
352}
353
354static inline swp_entry_t make_writable_migration_entry(pgoff_t offset)
355{
356 return swp_entry(0, 0);
357}
358
359static inline int is_migration_entry(swp_entry_t swp)
360{
361 return 0;
362}
363
364static inline void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep,
365 spinlock_t *ptl) { }
366static inline void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
367 unsigned long address) { }
368#ifdef CONFIG_HUGETLB_PAGE
369static inline void __migration_entry_wait_huge(pte_t *ptep, spinlock_t *ptl) { }
370static inline void migration_entry_wait_huge(struct vm_area_struct *vma, pte_t *pte) { }
371#endif /* CONFIG_HUGETLB_PAGE */
372static inline int is_writable_migration_entry(swp_entry_t entry)
373{
374 return 0;
375}
376static inline int is_readable_migration_entry(swp_entry_t entry)
377{
378 return 0;
379}
380
381static inline swp_entry_t make_migration_entry_young(swp_entry_t entry)
382{
383 return entry;
384}
385
386static inline bool is_migration_entry_young(swp_entry_t entry)
387{
388 return false;
389}
390
391static inline swp_entry_t make_migration_entry_dirty(swp_entry_t entry)
392{
393 return entry;
394}
395
396static inline bool is_migration_entry_dirty(swp_entry_t entry)
397{
398 return false;
399}
400#endif /* CONFIG_MIGRATION */
401
402typedef unsigned long pte_marker;
403
404#define PTE_MARKER_UFFD_WP BIT(0)
405#define PTE_MARKER_SWAPIN_ERROR BIT(1)
406#define PTE_MARKER_MASK (BIT(2) - 1)
407
408static inline swp_entry_t make_pte_marker_entry(pte_marker marker)
409{
410 return swp_entry(SWP_PTE_MARKER, marker);
411}
412
413static inline bool is_pte_marker_entry(swp_entry_t entry)
414{
415 return swp_type(entry) == SWP_PTE_MARKER;
416}
417
418static inline pte_marker pte_marker_get(swp_entry_t entry)
419{
420 return swp_offset(entry) & PTE_MARKER_MASK;
421}
422
423static inline bool is_pte_marker(pte_t pte)
424{
425 return is_swap_pte(pte) && is_pte_marker_entry(pte_to_swp_entry(pte));
426}
427
428static inline pte_t make_pte_marker(pte_marker marker)
429{
430 return swp_entry_to_pte(make_pte_marker_entry(marker));
431}
432
433static inline swp_entry_t make_swapin_error_entry(void)
434{
435 return make_pte_marker_entry(PTE_MARKER_SWAPIN_ERROR);
436}
437
438static inline int is_swapin_error_entry(swp_entry_t entry)
439{
440 return is_pte_marker_entry(entry) &&
441 (pte_marker_get(entry) & PTE_MARKER_SWAPIN_ERROR);
442}
443
444/*
445 * This is a special version to check pte_none() just to cover the case when
446 * the pte is a pte marker. It existed because in many cases the pte marker
447 * should be seen as a none pte; it's just that we have stored some information
448 * onto the none pte so it becomes not-none any more.
449 *
450 * It should be used when the pte is file-backed, ram-based and backing
451 * userspace pages, like shmem. It is not needed upon pgtables that do not
452 * support pte markers at all. For example, it's not needed on anonymous
453 * memory, kernel-only memory (including when the system is during-boot),
454 * non-ram based generic file-system. It's fine to be used even there, but the
455 * extra pte marker check will be pure overhead.
456 */
457static inline int pte_none_mostly(pte_t pte)
458{
459 return pte_none(pte) || is_pte_marker(pte);
460}
461
462static inline struct page *pfn_swap_entry_to_page(swp_entry_t entry)
463{
464 struct page *p = pfn_to_page(swp_offset_pfn(entry));
465
466 /*
467 * Any use of migration entries may only occur while the
468 * corresponding page is locked
469 */
470 BUG_ON(is_migration_entry(entry) && !PageLocked(p));
471
472 return p;
473}
474
475/*
476 * A pfn swap entry is a special type of swap entry that always has a pfn stored
477 * in the swap offset. They are used to represent unaddressable device memory
478 * and to restrict access to a page undergoing migration.
479 */
480static inline bool is_pfn_swap_entry(swp_entry_t entry)
481{
482 /* Make sure the swp offset can always store the needed fields */
483 BUILD_BUG_ON(SWP_TYPE_SHIFT < SWP_PFN_BITS);
484
485 return is_migration_entry(entry) || is_device_private_entry(entry) ||
486 is_device_exclusive_entry(entry);
487}
488
489struct page_vma_mapped_walk;
490
491#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
492extern int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw,
493 struct page *page);
494
495extern void remove_migration_pmd(struct page_vma_mapped_walk *pvmw,
496 struct page *new);
497
498extern void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd);
499
500static inline swp_entry_t pmd_to_swp_entry(pmd_t pmd)
501{
502 swp_entry_t arch_entry;
503
504 if (pmd_swp_soft_dirty(pmd))
505 pmd = pmd_swp_clear_soft_dirty(pmd);
506 if (pmd_swp_uffd_wp(pmd))
507 pmd = pmd_swp_clear_uffd_wp(pmd);
508 arch_entry = __pmd_to_swp_entry(pmd);
509 return swp_entry(__swp_type(arch_entry), __swp_offset(arch_entry));
510}
511
512static inline pmd_t swp_entry_to_pmd(swp_entry_t entry)
513{
514 swp_entry_t arch_entry;
515
516 arch_entry = __swp_entry(swp_type(entry), swp_offset(entry));
517 return __swp_entry_to_pmd(arch_entry);
518}
519
520static inline int is_pmd_migration_entry(pmd_t pmd)
521{
522 return is_swap_pmd(pmd) && is_migration_entry(pmd_to_swp_entry(pmd));
523}
524#else /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
525static inline int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw,
526 struct page *page)
527{
528 BUILD_BUG();
529}
530
531static inline void remove_migration_pmd(struct page_vma_mapped_walk *pvmw,
532 struct page *new)
533{
534 BUILD_BUG();
535}
536
537static inline void pmd_migration_entry_wait(struct mm_struct *m, pmd_t *p) { }
538
539static inline swp_entry_t pmd_to_swp_entry(pmd_t pmd)
540{
541 return swp_entry(0, 0);
542}
543
544static inline pmd_t swp_entry_to_pmd(swp_entry_t entry)
545{
546 return __pmd(0);
547}
548
549static inline int is_pmd_migration_entry(pmd_t pmd)
550{
551 return 0;
552}
553#endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
554
555#ifdef CONFIG_MEMORY_FAILURE
556
557/*
558 * Support for hardware poisoned pages
559 */
560static inline swp_entry_t make_hwpoison_entry(struct page *page)
561{
562 BUG_ON(!PageLocked(page));
563 return swp_entry(SWP_HWPOISON, page_to_pfn(page));
564}
565
566static inline int is_hwpoison_entry(swp_entry_t entry)
567{
568 return swp_type(entry) == SWP_HWPOISON;
569}
570
571#else
572
573static inline swp_entry_t make_hwpoison_entry(struct page *page)
574{
575 return swp_entry(0, 0);
576}
577
578static inline int is_hwpoison_entry(swp_entry_t swp)
579{
580 return 0;
581}
582#endif
583
584static inline int non_swap_entry(swp_entry_t entry)
585{
586 return swp_type(entry) >= MAX_SWAPFILES;
587}
588
589#endif /* CONFIG_MMU */
590#endif /* _LINUX_SWAPOPS_H */